1. Field of the Invention
This invention relates to improvements in tools designed to manipulate wheel-mounted tires while installing and removing them from a vehicle. It also relates to tools provided for spinning lug nuts onto and off of lugs.
2. Description of Related Art
Vehicles having pneumatic wheel-mounted tires provide lugs, usually concentric an axle hub, which cooperate with lug holes in the wheel for removably attaching the wheel to the vehicle. A single operator may be called upon to change a flat tire on a vehicle by swapping it for an inflated spare carried for such emergencies, but the task can prove too difficult for some operators without assistance. It usually requires lifting the wheel and tire into position and supporting their combined weight while stooping to align the lug holes with the lugs. On many vehicles, the lugs are recessed within a wheel well surrounded by the vehicle body such that lifting the tire must be performed in an awkward position, a formidable task for many and threatening to cause back strain even if the driver is accustomed to the task. Even wheel-mounted tires for personal vehicles can weigh scores of pounds, and, for relatively frail or incapacitated drivers alone, in the dark or during inclement weather, the task may prove daunting if not impossible. A need therefore exists for a tool to facilitate lifting and aligning spare tires.
Lug nuts often prove problematic during installation and removal. Lugs become dirty and corroded, increasing friction and making hand turning of the nuts unusually difficult. Further, tightening the nuts sufficiently for safe operation of the vehicle, and loosening them for removal of the tire, invariably requires the assistance of a wrench. An asymmetric combination tool, having on one end a socket adapted to fit the lug nuts, often is included with the spare tire of a given vehicle, but this standard tool at best proves itself tedious to use for turning the nuts onto and off of the lugs. As a lifting lever, the standard tire tool is usually too short and has but one "leg" with which to reach under the tire tread and pry upward. An "X", or cross-shaped tool, commonly known as a lug wrench, works better for quickly removing lug nuts because it has a lug socket on each end of two legs affixed perpendicular to each other at their midpoints. One end of one of the legs provides a built in handle for supporting the lug wrench while spinning the nuts on the lugs using the socket on the other end of that leg, while the transverse legs provide handy torquing lever arms. A lug wrench does not serve well, however, as a tire lifting and manipulating tool. Particularly when installing the wheel, two legs greatly facilitate supporting the tire and deter unwanted rolling while aligning lug holes with lugs. Used in this fashion, however, a lug wrench provides no central handle for manipulating the tool and tire. A need therefore exists for a single tool that can serve not only as a lug nut spinning and tightening tool, but also as a tire lifting and manipulating tool when not being used to adjust lug nuts.
In commercial frame and axle repair shops, large wheel-mounted truck or tractor tires weighing several hundred pounds must be manipulated during installation and removal. Merely erecting such a tire from its position lying flat on the floor to standing upright on its tread can require a lever tool or the assistance of another person. A forked tool providing two point support to the tire significantly improves upon the controllability of a single lever for this task. Mechanics often also overcome with shear muscle power the awkwardness of installing tires within a recessed wheel well of a large truck. This is particularly awkward when installing or removing the inside wheel of a tandem wheel hub, the center of gravity of the wheel requiring manipulation of its weight even deeper under the vehicle and beyond the support point of the hub. A need therefore exists for a means for lifting and manipulating very large truck and tractor wheel-mounted tires during installation and removal.
Of several devices available for lifting and handling tires, none combine these features with lug nut torquing or spinning conveniences. Smischny, U.S. Pat. No. 2,195,635, provides a tool having a short pair of prongs flaring slightly and extending into a different plane from one end of a generally U-shaped handle. For numerous reasons, however, this device serves poorly for lifting any but the lightest weight tires. For example, the handle is too wide relative to the prongs. For maximum control in lifting heavy tires, an operator must stand alongside the tool and reach to his side to grasp the handle in its center. The further the operator must reach to the side, the further off balance the weight of the tire becomes during lifting, increasing the consequent back strain and risk of injury. Further, the short prongs require lifting the handle end through a great range of motion relative to the small amount of accomplished lift of the tire edge.
Several combination tools offer lifting and lug nut torquing features together in one tool, but none provide well any lug nut spinning capabilities like a lug wrench. Isom, U.S. Pat. No. 3,649,976, and Nellis, U.S. Pat. No. 2,504,345, both provide rectangular, fork-shaped lifting tools with sockets on the end of the handle opposite the fork. Relying on these sockets for spinning lug nuts is at best awkward, however, because the user must reach around the fork to grasp the handle. Miller, U.S. Pat. Nos. 2,701,707 and 2,619,320, provides two "hairpin" shaped tools having transverse arms bearing lug nut sockets, but the asymmetric hairpin shaped lever arms provide poor torquing leverage.